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1.
用制霉菌素穿孔膜片钳方法研究5-HT和NA对急性分离的大鼠骶髓后连合核神经元甘氨酸门控氯离子通道电流(IGly)的调控作用及其胞内机制。发现:(1)5-HT激活与非胰岛激活蛋白(IAP)敏感型G蛋白偶联的5-HT2受体亚型,激活磷脂酶C(PLC),增加甘油二酯(DAG)的生成。DAG增强不依赖Ca2+的新型PKC(nPKC)的活性,从而增强IGly;(2)NA激活与IAP敏感型G蛋白偶联的α2受体,抑制腺苷酸环化酶(AC),减少cAMP的生成,使PKA活性降低,从而增强IGly。 相似文献
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小鼠2—细胞期经电融合后的早期胚胎发育 总被引:1,自引:0,他引:1
小鼠2-细胞期经电融合后的早期胚胎发育小鼠,电融合,细胞数,核型,四倍体胚胎小鼠2细胞期经电融合后的早期胚胎发育EARLYDEVELOPMENTOFMOUSEEMBRYOSPRODUCEDBYELECTROFUSIONAT2CELLSTAGE关键... 相似文献
3.
汪浩川等研究表明一定量Ox-LDL能刺激培养人动脉SMC细胞的增殖[1],Dejager等采用交叉抑制实验证明兔SMC细胞膜上有能结合Ox-LDL的清道夫受体[2],因此Ox-LDL诱导培养人SMC细胞增殖可能是Ox-LDL作用于SMC膜清道夫受体后... 相似文献
4.
天然及氧化修饰脂蛋白对人动脉平滑肌细胞原癌基因… 总被引:8,自引:1,他引:8
动脉平滑肌细胞(SMC)的增殖在动脉粥样硬化(AS)的形成过程中极其重要。我们在建立人主动脉SMC体外培养方法的基础上,观察了LDL,VLDL及HDL和相应的氧化修饰型脂蛋白对培养人SMC sis,jun,H-ras原癌基因及Rb抗癌基因转录表达的影响。结果表明:(1)HDL对SMCsis,jun,ras基因表达无影响;(2)LDL和VLDL有使这些基因表达增加的趋势;(3)ox-LDL,ox-V 相似文献
5.
从毛裂蜂斗菜(pdtasilex tricholobus Franch。)的石油醚提取物中首次分离得到6个化合物,运用IR,EI-MS,HRMS,^1H NMR,^13C NMR,DEPT等光谱方法确定了它们的结构。它们分别是:A1-β-谷甾醇;A2,三十二碳酸,A3,羽扇豆醇;A4,Bakkenolide-B;A5,Bakkenolide-D和A6,akkenolide-E。 相似文献
6.
本次首次建立了从小鼠肝脏分离、培养、扩增肝树突状细胞(hepaticdendriticcel,HDC)前体的方法。采用经门静脉插管胶原酶二步循环灌流法及Percol不连续密度梯度离心法分离非肝细胞,得到含HDC前体组分,将其分三组培养:第一组加入重组小鼠粒细胞/巨噬细胞集落刺激因子(MrGMCSF),待培养9天后,将细胞转移至鼠尾胶原上继续培养。第二组加入MrGMCSF培养,但细胞不转移。第三组为对照组,仅加完全培养液。结果显示:第一、二组细胞于培养4天可见有许多细胞集落形成,第一组细胞转移至鼠尾胶原上培养1天后,细胞集落减少,而培养液中DC密度明显增加,光镜和扫描、透射电镜观察证明培养HDC纯度达95%,第二组则无上述细胞释放现象。实验结果提示,HDC前体在体外受细胞因子刺激能大量扩增,但必须在胶原存在下才能分化成熟 相似文献
7.
DDPH[1-(2.6-二甲基苯乙氧基)-2-(3.4二甲氧基苯乙胺基)丙烷盐酸盐]是南京药科大学合成的降压新化合物,也具有降低肺动脉高压和抑制肺动脉平滑肌细胞增殖作用。本实验用细胞培养、免疫细胞化学、图像分析、3H-TdR、细胞周期测定等方法,进一步探讨DDPH对缺氧性肺动脉平滑肌细胞(PASMCS)增殖的抑制机制。结果:缺氧促进肺动脉内皮细胞(PAECs)的PDGF·BB和bFGF两种生长因子的表达(积分光密度OD值)增高。缺氧内皮细胞条件培养液(HECCM)能促进PASMCS的PDGF·BB的OD值增高,bFGF的OD值无明显改变。加药组(HEC-CM+DDPH)的PDGF·BB和bFGF的OD值均显著降低,尤以PDGF·BB的OD值减少最多.提示:DDPH能抑制HECCM引起PASMCS的PDGF·BB和bFGF表达增多和细胞增殖。结果与大鼠实验观察相符。 相似文献
8.
本工作采用荧光探针Fura-2AM观察了外源性神经节苷脂GM3和GD3对SMMC-7721人肝癌培养细胞钙的影响,证明GM3和GD3均能升高细胞内钙浓度([Ca2+]i),但程度上有极大差异。10nmol/mLGM3或1.0nmol/mLGD3可使[Ca2+]i上升高是明显,与对照相比[Ca2+]i分别增加215~250%和42%。进一步用Verapamil阻断钙通道和内质网钙释放、去除细胞外Na+以抑制Na+-Ca2+交换以及去除细胞外Ca2+在无外钙内流等系统观察了GM3和GD3的作用方式,结果提示GM3升高[Ca2+]i的机制是一个同时增加内质网钙释放、激活钙通道并伴有质膜Ca2+-ATP酶激活的综合结果;而GD3则主要抑制Na+-Ca2+交换系统。 相似文献
9.
外源IAA 处理可以显著增加小麦胚芽鞘细胞NAD 激酶的催化活性,钙离子可以增强IAA 的作用效果,而钙离子通道抑制剂LaCl3 则起强烈的抑制作用,但在存在钙离子的条件下,这种抑制作用可以被钙离子载体A23187 消除;钙调蛋白能够在离体条件下激活经过DEAE 纤维素柱纯化的小麦胚芽鞘NAD激酶,经过IAA 处理的胚芽鞘细胞中能够刺激NAD 激酶活性的钙调蛋白含量明显增加,IAA 的这一作用受LaCl3 的抑制。上述结果表明Ca2+ /CaM 复合物介导了生长素对小麦胚芽鞘细胞NAD 激酶活性的促进作用。 相似文献
10.
采用荧光染料 Di B A C4(3), Fluo3/ A M 和 S N A L F Calcein/ A M 分别标记小鼠骨髓基质细胞( B M S C),在激光扫描共聚焦显微镜下直接监测重组人白细胞介素1β( I L1β)刺激后细胞膜电位,细胞内游离 Ca2+ 浓度和胞浆 p H 的实时动态变化. 结果发现: I L1β加入测定体系后浓度依赖性地引起 B M S C 膜电位的迅速改变. 低浓度时发生去极化反应,高浓度时发生超极化反应. 非受体方式作用的 I L1β肽段 163171 对膜电位无影响. I L1β不影响细胞内 Ca2+ 的浓度和胞浆p H. 研究表明膜电位的变化为 I L1 受体后早期事件,它与细胞内 Ca2+的浓度和胞浆 p H 的调节无关. 相似文献
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12.
Jean‐Philippe Pellois 《BioEssays : news and reviews in molecular, cellular and developmental biology》2019,41(6)
The confluence of protein engineering techniques and delivery protocols are providing new opportunities in cell biology. In particular, techniques that render the membrane of cells transiently permeable make the introduction of nongenetically encodable macromolecular probes into cells possible. This, in turn, can enable the monitoring of intracellular processes in ways that can be both precise and quantitative, ushering an area that one may envision as cellular biochemistry. Herein, the author reviews pioneering examples of such new cell‐based assays, provides evidence that challenges the paradigm that cell penetration is a necessarily damaging and stressful event for cells, and highlights some of the challenges that should be addressed to fully unlock the potential of this nascent field. 相似文献
13.
Ultrastructural evidence for two-cell and three-cell neural pathways in the tentacle epidermis of the sea anemone Aiptasia pallida. 总被引:2,自引:0,他引:2
Sensory and ganglion cells in the tentacle epidermis of the sea anemone Aiptasia pallida were traced in serial transmission electron micrographs to their synaptic contacts on other cells. Sensory cell synapses were found on spirocytes, muscle cells, and ganglion cells. Ganglion cells, in turn, synapsed on sensory cells, spirocytes, muscle cells, and other neurons and formed en passant axo-axonal synapses. Axonal synapses on nematocytes and gland cells were not traced to their cells of origin, i.e., identified sensory or ganglion cells. Direct synaptic contacts of sensory cells with spirocytes and sensory cells with muscle cells suggest a local two-cell pathway for spirocyst discharge and muscle cell contraction, whereas interjection of a ganglion cell between the sensory and effector cells creates a local three-cell pathway. The network of ganglion cells and their processes allows for a through-conduction system that is interconnected by chemical synapses. Although the sea anemone nervous system is more complex than that of Hydra, it has similar two-cell and three-cell effector pathways that may function in local responses to tentacle contact with food. 相似文献
14.
哺乳动物体细胞核移植中供体细胞的研究进展 总被引:2,自引:0,他引:2
在哺乳动物体细胞核移植中,供体细胞是影响其效率的主要因素之一。供体细胞的类型、细胞周期、细胞的培养代数、冷藏与冷冻处理,以及供体动物的性别、年龄等都可能影响核移植胚胎的发育。根据现有资料,简要综述了在哺乳动物体细胞核移植中有关供体细胞的研究进展。 相似文献
15.
M Wirén K.E Magnusson J Larsson 《The international journal of biochemistry & cell biology》1998,30(12):1331-1336
Background: Glutamine is routinely added to most cell cultures. Glutamine has been found to be the preferential nutrient to the rapidly replicating intestinal mucosa, but whether this is a metabolic effect or due to other properties of this amino acid is not determined. To study the importance of glutamine on the growth of two enterocyte-like cell lines, the effects of depriving the media or supplementing it with glutamine were assessed in media with different serum and energy supplements. Methods: CaCo-2 and HT-29 cells were grown in serum-free medium, with fetal bovine or synthetic serum, and with or without glucose or galactose. The glutamine content was varied between 0 and 4 mM. All growth assays were performed in triplicate by counting in a hemocytometer. Results: Both cell lines were dependent of serum factors for growth, but displayed distinct requirements on glutamine supplementation. Glutamine was an obligate supplement with dose-dependent correlation to growth (r=0.87, p<0.01) for CaCo-2 cells cultured in synthetic, but not in fetal bovine serum. In HT-29 cells, the correlation between glutamine and growth was significant (r=0,68, p<0,05) only in fetal bovine serum in the absence of galactose. Conclusion: This study shows that glutamine has different growth stimulating effects on two enterocyte-like cell lines studied. This could reflect different modes of action of glutamine on proliferation and differentiation in an enterocyte cell population. 相似文献
16.
Müller HA 《Development, growth & differentiation》2001,43(4):327-342
Embryonic development begins with cleavage of the fertilized egg. Cleavage comprises two major processes: cytokinesis and formation of a polarized epithelial cell layer. The focus of this review is comparison of the generation of membrane polarity during embryonic cleavage in three different developmental model systems. In mammalian embryos, as exemplified by analysis of the mouse, generation of distinct membrane domains is uncoupled from cleavage divisions and is initiated in a specific developmental phase, called compaction. In Xenopus laevis embryos, generation of polarized blastomeres occurs simultaneously with cytokinesis. The origin of specific membrane domains of X. laevis polar blastomeres, however, can be traced back to oogenesis. Finally, in Drosophila melanogaster, generation of polarized cells occurs at cellularization. The relevance of cell adhesion, cell junctions and cytocortical scaffolds will be discussed for each of the model systems. Despite enormous morphologic differences, the three models share many common features; in particular, many important molecular interactions are conserved. 相似文献
17.
微囊化K562细胞生长周期及代谢特性的研究 总被引:1,自引:0,他引:1
以K562细胞为模型,分别进行微囊化和游离培养,运用流式细胞术考察两种培养体系下细胞周期和生长代谢变化;建立数学模型,模拟了两种培养体系下细胞的生长活性和代谢特性。实验发现:微囊化培养过程中的K562细胞处于DNA合成期(S期)的百分含量显著高于游离培养,并且细胞保持较高的增殖活性。模型计算表明,所建模型动力学参数能够很好地描述微囊化和游离两种培养体系下细胞的代谢情况;对细胞活性的理论计算表明,微囊化的细胞具有较高的增殖和代谢活性,同时细胞能够较长时间保持此活性;模型参数表明,两种培养体系下,葡萄糖对细胞生长的影响无显著差别
(kFreeL≈kAPAL),乳酸对游离培养细胞的生长具有明显抑制作用,但对微囊化培养细胞抑制作用较小(kFreeL>≈kAPAL)。 相似文献
18.
《Cell communication & adhesion》2013,20(3):181-191
AbstractThis review article discusses a recent work using engineered cardiac cells to study the function of the intercalated disc putting emphasis on mechanical and electrical coupling. 相似文献
19.
ABSTRACT
We fabricated uniform straw-like cell architecture with central lumen using a suture thread within 1 h. The architecture consisting of cancer cells and mature adipocyte was used for cell–cell communication assay, although mature adipocyte could not form spontaneous multi-cellular spheroids. Using the system, it is possible to investigate three-dimensional cell–cell communication as an alternative to animal experiments. 相似文献
20.
Yomgogida K 《Development, growth & differentiation》2008,50(6):513-515
Mammalian spermatogenesis consists of three biologically significant processes: stem cell self-renewal and differentiation, meiosis, and haploid cell morphogenesis. Understanding the molecular mechanisms behind these processes might provide clues to the puzzle of species preservation and evolution, and to treatments for male infertility. However, few useful in vitro systems exist to investigate these processes at present. To elucidate these mechanisms, in vivo electroporation of the testis might be a convenient option. Since DNA solution can be injected into the seminiferous tubule via the rete testis, similar to germ cell transplantation, it is easy to transfect expression vectors into various differentiated germ cells and supporting Sertoli cells with adequate electric shock. Unfortunately, it is difficult to create transgenic animals using this method because of its low efficiency. However, gain- and loss-of-function assays, promoter assays, and tagged-protein behavior assays can be conducted with this technique, as in in vitro culture systems. 相似文献